Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations provided, the description carries the full burden. It discloses what the tool returns (id, public ingest url, inbox_url, signing secret) and highlights the idempotent behavior of external_ref: 'idempotent re-provisioning and re-finding.' This provides useful behavioral context beyond the schema, though it does not cover every edge case (e.g., default values or environment handling).

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is three sentences long, front-loaded with the primary action and return values, then a focused tip about external_ref. No wasteful or redundant text; every sentence earns its place.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a creation tool with no output schema and no annotations, the description is quite complete: it explains the purpose, key return values, and the idempotency mechanism. It does not describe the format of the returned values or any potential limits, but given the tool's simplicity and the schema's coverage, this is sufficient.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so the schema already documents all three parameters. The description adds extra meaning for external_ref by giving a concrete example ('acme-api:stripe') and explaining how it enables re-finding with list_buckets, which goes beyond the schema's description. Name and environment are not elaborated, but the schema already covers them adequately.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool's function: 'Provision a new webhook endpoint (a "bucket") that captures incoming HTTP requests.' It uses a specific verb (provision) and resource (webhook endpoint/bucket), and distinguishes itself from siblings like delete_bucket and list_buckets by explicitly being the creation tool.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description implies when to use this tool (to create a new webhook endpoint) and provides a concrete usage tip: pass external_ref to re-find the bucket later with list_buckets. It does not explicitly list alternatives or exclusions, but the creation use case is clear and the reference to list_buckets guides follow-up actions.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.